LDEO Seismology: Long-Period Noise

ADK-IU , LHN-00

Noise Levels at Different Periods

The table below gives the decibel 10% noise level (in db) for each month in several period bands. The 10% noise level is defined as the signal level not exceeded 10% of the time, based on hourly measurements. Each entry in the table is color coded with reference to the New Low Noise Model (NLNM, Peterson, 1993):
navy, -6 db < value-NLNM < -3 db
blue, -3 db < value-NLNM < 3 db
aqua, 3 db < value-NLNM < 6 db
lime, 6 db < value-NLNM < 9 db
yellow, 9 db < value-NLNM < 12 db
orange, 12 db < value-NLNM < 15 db
red, 15 db < value-NLNM < 20 db
fuchsia, 20 db < value-NLNM < 25 db
silver, value-NLNM < -6 db, value-NLNM > 25 db

Black indicates that there was an insufficient number of hourly measurements to calculate a noise level.

Noise levels (PSD) in decibels
Month Chan. Qual. # obs. 268s 228s 193s 164s 139s 118s 100s 85s 72s 61s 52s 44s 37s 32s 27s 23s 19s 16s 14s 12s 10s

200902 LHN-00 AR 96 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

200901 LHN-00 AR 76 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

200812 LHN-00 AR 149 -138 -137 -137 -137 -137 -138 -138 -141 -140 -141 -142 -142 -144 -145 -145 -146 -145 -142 -140 -139 -139

200811 LHN-00 AR 238 -145 -146 -145 -146 -147 -147 -148 -149 -149 -149 -149 -150 -151 -151 -151 -152 -151 -150 -149 -145 -143

200810 LHN-00 AR 253 -145 -145 -146 -146 -146 -147 -148 -148 -149 -150 -150 -150 -151 -152 -153 -153 -152 -151 -150 -150 -146

200809 LHN-00 AR 99 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

200808 LHN-00 AR 29 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

Month	Chan.	Qual.	# obs.	268s	228s	193s	164s	139s	118s	100s	85s	72s	61s	52s	44s	37s	32s	27s	23s	19s	16s	14s	12s	10s
200902	LHN-00	AR	96	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
200901	LHN-00	AR	76	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
200812	LHN-00	AR	149	-138	-137	-137	-137	-137	-138	-138	-141	-140	-141	-142	-142	-144	-145	-145	-146	-145	-142	-140	-139	-139
200811	LHN-00	AR	238	-145	-146	-145	-146	-147	-147	-148	-149	-149	-149	-149	-150	-151	-151	-151	-152	-151	-150	-149	-145	-143
200810	LHN-00	AR	253	-145	-145	-146	-146	-146	-147	-148	-148	-149	-150	-150	-150	-151	-152	-153	-153	-152	-151	-150	-150	-146
200809	LHN-00	AR	99	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
200808	LHN-00	AR	29	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999